Improvement in



JOHNSTON & DOW.

Cartridge.

Patented May ID QWK N.PETERs. PHOTO-LITHOGRAPHER. WASHINGTON. D 1.

STATES PATENT FFICE.

ALGERNON K. JOHNSTON AND LORENZO DOW, OF NEW YORK, N. Y.

IMPROVEMENT IN APPLYING PERCUSSION-PRIMING- TO CARTRIDGES.

Specification forming part of Letters Patent No. 42,667, dated May 10, 1864.

To all whom it may concern Be it known that we, ALGERNON K. J OHNS- TON and LORENZO Dow, of the city, county,

and State of New York, have invented a new and Improved Percussion-Cap to be attached to a Cartridge-Case; and we do hereby declare that the following is a full, clear, and exact description of the construction of the same, reference being had to the annexed drawings, making a part of this specification.

The figures represent sectional views.

WVe first make a cup of the form represented in Figure 1, of metal or other hard substance. The circumference of the base of this cup should be slightly larger than that of the base of the cartridge to which it is designed to attach the cap, so that the cap may slightly project at its edge all around the base of the cartridge when attached, say the twelfth part of an inch. The upright sides ofthe cup a a should be nearly as long as half of the diameter of the base of the cup, so that when bent over, as hereinafter described, they may come nearly or quite to the tube in the center of the disk, Fig. 2. This disk is made of metal or other hard substance, and is acircular plate of size such that it will exactly fit the bottom of the cup. In the center of this disk is a small hole, say one-twelfth of an inch in diameter, from which projects a short tube, a seetional view of which is seen at b in Fig. 2. Thedisk then forms a wide flange around the tube I). (Shown in Figs. 2 at e c.) This tube may be longer or shorter, as desired, its object being 'to conduct the flame from the fulminating-powder to the charge in the cartridge-case. The tube might be dispensed with, leaving the hole in the disk alone communicating with an aperture in the base of the cartridge; but we prefer the tube, or some projection in its place, as, in addition to its forming a complete opening for the flame, it is of use in attaching the cap to the cartridge and in the handling of the parts. We then moisten the disk and dip it in fulminatingpowder or spread the powder over it, and then place the disk within the cup, as shown in Fig. 3. Then we bend the sides of the cup a a upon the flange of the disk 0 e, and press them firmly but carefully together. When the sides of the cup are thus pressed down upon the disk, with the fulminate between the bottom of the cup and the disk, the cap is complete, as shown in Fig. 4, and it may then be attached to the cartridgercase.

Instead ofdrawin g the projecting tubein the disk, it may be drawn in the center of the base of the cup, as represented in Fig. 5, the tube being represented at b, and the sides of the cup at a a. In this case the disk will have no tube in it, but be simply a thin circular plate. This is moistened and then dipped in t'ulminating-powder, as before, and placed in the cup, the edges of which are then pressed down upon the disk, and the cap is thus formed. In this case the communication with the charge in the cartridge is through the base of the cup; in the other it is through the aperture in the disk. Either method makes the same cap but the former is neater, as it leaves a smooth surface on the outside when the cap is attached to the cartridge-case.

What we claim as our invention, and desire to secure by Letters Patent, is-- The use of a disk in connection with a cup, and held in close juxtaposition to its base by turning the edges of the cup, substantially as above described, together with a tube communicating with the fulmiuating-powder on the disk at the base of the cup, either through that or through the disk, in the manner above set forth.

ALGERNON K. JOHNSTON. LORENZO DOW.

Witnesses:

JULIUS R. POMEROY, WILLIAM H. BOUGHTON. 

